Hot water heating systems having auxiliary pressurizing means



1965 D. B. GARDNER ETAL 3,202,356

HOT WATER HEATING SYSTEMS HAVING AUXILIARY PRESSURIZING MEANS Filed Dec. 28

Du hE ONW M E R M V A m E wK AN NA OR DF ATTORNEY United States Patent 3,292,356 HOT WATER HEATING SYSTEMS HAVING AUX- ILHARY PRESSURIZING WAN Donald B. Gardner, Mount Prospect, and Frank E.

Dameron, Chicago, Ill., assignors to international Telephone and Telegraph Corporation, New York, N.Y., a corporation of Maryland Filed Dec. 28, 1962, Ser. No. 247,892 1 Claim. (U1. 237-8) This invention relates to improvements in hot water systems having an auxiliary pressurized vessel for releasing and receiving quantities of water to and from the system made necessary by expansion of the system, and more particularly to structure for providing ready miscibility of the pressurizing medium when heating liquid is returned to the auxiliary vessel.

Pressurized hot water heating systems present an advantage over vapor systems operating at small gauge pressure in that the heating medium can be maintained at temperatures greatly in excess of 212 F. However, by reason of the expansion in the water in the system structure must be provided for valving oil excess water, and upon cooling of the system and contraction of the water, air is introduced into the system with its consequent corrosive efl'ect.

According to the invention herein an auxiliary quiescent pressure vessel is provided to store the expanded water upon heating thereof, and to return the water to the system upon contraction thereof, an auxiliary boiler being provided to apply pressure to the auxiliary vessel, structure being provided for causing miscibility of the water returning to the auxiliary vessel with the steam pressurizing medium.

It is a principal object of this invention to provide a pressurized hot water system characterized by an auxiliary pressurized vessel adapted to receive expanded water from the system, or to return water to the system upon cooling thereof, together with structure for providing ready miscibility of the expanding water returning to the auxiliary vessel with the pressurizing medium.

Other objects and important features of the invention will be apparent from a study of the following specification taken with the drawing, which together describe and illustrate a preferred embodiment of the invention, and what is now considered to be the best mode of practicing the principles thereof. Other embodiments may be suggested to those having the benefit of the teachings herein and such other embodiments are intended to be reserved especially as they fall within the scope and spirit of the subioined claim.

In the drawing, the single figure illustrates a closed pressurized hot water heating system having the improvements according to the present invention embodied therein.

Referring now to the drawing, the improved hot water heating system embodying the improvements according to the present invention is referred to by the reference numeral 1%, and includes a boiler 11 connected in a pressurized heating system including a supply line 12 and a return line 13. An air separator lid is connected in the return line 13, and a pump 16 provides for circulation of heated liquid through the supply and return lines 12. and 13.

Apparatus for supplying heat for the boiler is not shown, and the control of such apparatus may be by thermostats or other devices located in areas it is desired to heat. Details of such structure forms no part of the present invention, and accordingly is not shown herein.

Irrespective of the manner of control of the boiler ll, the areas to be heated comprise radiation elements 17 3,202,356 Patented Aug. 24, 1965 which may be located in separate areas, these radiation elements 17 being connected across the supply and return lines 12 and 13.

Structure is provided for accommodating the change in volume of liquid as the liquid is heated, such structure including an auxiliary pressurizing vessel 18 connected by a line 19 to the return line 13 adjacent the intake or suction side of the circulating pump 16.. The auxiliary vessel 18 is adapted to retain a quiescent body of liquid L which varies in volume according to the heat applied to the boiler ll and to the circuit comprising the supply and return lines 12 and 13 and the radiation elements 17.

Structure is provided for applying pressure to a volume V above the liquid L, within the auxiliary pressurizing vessel 1%, and includes a small boiler 21 which is heated by a heating element 22. Heating element 22 is ener gized from any convenient source, and is under the control of a pressure sensing device 23 connected by a line 24 back to the heating element 22 for the control thereof.

The level of liquid within the boiler 21 is under the control of a float actuated switch 26 connected in the line 27 to control the operation or" a pump 28 connected in a line 29 connecting the auxiliary vessel 18 and the boiler 21. A check valve 31 prevents the flow of liquid from the boiler 21 back to the auxiliary vessel 18.

The auxiliary vessel 18 is adapted to be filled from a city water supply, not shown, but connected thereto by a supply line 32. A fill valve 33 is connected in the supply line 32, and the line 32 is connected to the lower end of the auxiliary tank for the filling thereof as well as the heating system previously described.

A fill tank 34 is connected by a supply line 36 branching from the fill line 32, :and the liquid level within fill tank 34 is controlled by a fioat operated valve 35.

The level of liquid within the auxiliary pressurizing vessel 18 is controlled by a lower float operated switch 37 connected in a power lead 38 to a motor operated pump 39 located in a supply line 4-1 from the fill tank 34 to the auxiliary pressurizing tank 18. A check valve 42 is connected in the line 41 between the out-put of the pump 39 and the tank 18 to prevent the how in a reverse direction. The fioat operated switch 37 is adapted to control the energization of the motor operated pump 39 when the level of liquid in the auxiliary vessel 1% falls to a certain level.

A normally closed motor driven return valve 43 is connected in a pipe 44 between the fill tank 34 and the line 32 connected to the lower end of the auxiliary tank 18. Return valve 43 has a solenoid operator 45 and is under the control of an upper float operated switch 46 connected by a control lead 47 to the return valve 43. Thus, when the level of the liquid in the auxiliary vessel 18 rises above :a predetermined level, the excess of liquid is returned at the valve 53 to the fill tank 34.

Pressure within the auxiliary tank 18 is relieved by a relief valve 48 connected in a pipe 49 leading from the fill tank 34 and to the line 32. Any excess of pressure in the liquid within the auxiliary vessel 18 is thus relieved by the relief valve 48.

Safety means are provided for insuring the shut off of the boiler 11 should the lower level in the tank 13 be maintained beyond a predetermined time. The float operated switch 37 controlling admission of new liquid from the fill tank 3 to the auxiliary pressure vessel 18 is accordingly connected to a control lead 51 which in turn is connected to an alarm and boiler shut-ofi mechanism 52. This mechanism is arranged to cut off the supply of heat to the boiler ll and to give at the same time an alarm to the operator that the level of liquid within the auxiliary vessel 18 is at too low a level. However, since the switch v) 37 is called upon from time to time to control the admission of liquid from the fill tank 34 to the auxiliary ves sel 18, the operation of the alarm and shut off 52 does not immediately occur, a suitable delaying mechanism being incorporated in the shut-01f mechanism 52 in a manner well known in the art.

Structure is provided for enabling expanded water returning from the system it) to have the steam present in the volume V above the liquid L in auxiliary vessel 18 to dissolve readily into the returning liquid. Without the provision of such structure, the rapid return of systern Water to vessel 18 would give rise to opening of relief valve 43 to discharge the returning water to the fill tank 34, with the possibility of overfill thereof.

Since the system water is characterized after continued use by removal of dissolved oxygen which has gone into combination with the system metal, and is inert, it is desirable to prevent the loss of non-corrosive system Water to the greatest extent possible.

To this end the line 19 connecting auxiliary vessel 18 to the return line 13 is extended within vessel 18 to a point above the maximum level encountered of liquid within such vessel. Line 19 accordingly has an extension or riser 53, the top of which is provided with a bubbling or trickling tray 54. The liquid returning from system 10 via line 19 and extension 53 flows over the peripheral portions of tray 54, and in so doing the descending curtain of system water has an opportunity to dissolve readily the vapor within volume V overlying the liquid L in vessel 18.

When liquid is returned to system 10, it can readily do so past a check valve 56 including a connection 57 to extension 53. It is evident that incoming liquid is checked at valve 56 and must go to the top of riser 53 and tray 54 as described.

It is believed" that the temperature of the liquid incoming to vessel 18 is at a lower temperature than the vapor of volume V pressurizing the system. By reason of this lower temperature water introduced into volume V, ready condensation of the vapor is had to lower the pressure and provide additional volume for entering water until the pressure builds up again by boiler 21.

It is believed evident that the water can return readily to the auxiliary vessel 18 without giving rise to undue increases in pressure causing operation of valve 48, and thus losing water from the system.

While the invention has been described in terms of a preferred embodiment thereof, it is intended that the same be limited only by the terms of the claim here ap'- pended.

We claim:

In a closed hot liquid heating system having a boiler and heat radiation structure connected therein, including means for circulating liquid through said radiation structure, an auxiliary pressurizing vessel connected to said system and adapted to receive a quiescent quantity of heating liquid which changes in amount according to the expansion or contraction of heating liquid in the system, an auxiliary pressurizing boiler of extremely small volume as compared to the volume of said auxiliary pressurizing vessel connected to said auxiliary pressurizing vessel for supplying vapor under pressure to the vapor space above the level of liquid contained in said auxiliary pressurizing vessel, means for applying heat to said pressurizing boiler including means responsive to the presure in said auxiliary pressurizing vessel for regulating said heat applying means; the improvement in said system in which said auxiliary pressurizing vessel is connected to said system by a pipe extending through the body of liquid in said auxiliary pressurizing vessel and terminating at a point above the maximum height of liquid therein, means supported within said auxiliary pressurizing vessel and providing for miscibility of vapor above the liquid in said auxiliary pressurizing vessel with the liquid returning from said system to said vessel by said pipe upon expansion of said liquid, and check valve means located between said pipe and the volume of liquid in said auxiliary pressurizing vessel whereby the liquid returning to said auxiliary pressurizing vessel returns thereto only by said pipe and said miscibility providing means.

References Cited by the Examiner UNITED STATES PATENTS 1,294,517 2/19 Motley 23761 2,753,120 7/56 Carlson 2378 2,888,204 5/59 Williams 23 8-8 3,095,012 6/63 McShane 23763 X 3,134,543 5/64 Carlson et al. 237-63 FOREIGN PATENTS 592,656 2/60 Canada. 451,367 10/27 Germany. 560,332 10/32 Germany.

4.5 OTHER REFERENCES Publication: Lieberg Hight Temperature Water Sys tems, The Industrial Press, New York 13, N.Y., 1958.

EDWARD J. MICHAEL, Primary Examiner. 

